LASER-INDUCED LASING IN CS2 VAPOR

When CS2, contained in a tube at pressures ranging from 350 to 450 mTo rr, was optically excited by a pulsed laser at a wavelength of 343.6 n m to the J = 29, upsilon = (0, 10, 0), R3B2 state (i.e., the SIGMA = 0 component of the a3 A2 state), six coherent emissions were observed a long the same axis from both ends of the tube. These emissions possess the characteristics of the pump laser, such as linewidth, pulse durat ion and polarization, but do not need a cavity to gain amplification. The emissions terminate on the high vibrational states of the ground e lectronic state. A time delay between the pump laser and the emissions was observed. The emission intensity depends non-linearly on the CS2 pressure and exhibits a third order power dependence. A cooperative st imulated emission model is proposed to explain this phenomenon.